Tank structure of heat exchanger

ABSTRACT

In a tank structure of a heat exchanger  1  where end portions of a plurality of tubes  8  are inserted in and fixed to a tube plate  5, 6  of a tank  3, 4  that is made of aluminum material, a bead  12   a  is provided at a position of a tube  8  side heading from a half position of a height H of a side wall portions  11   a  and  11   b  of the tank  3, 4  to extend in a direction perpendicular to a longitudinal direction of the tubes  8.

TECHNICAL FIELD

The present invention relates to a tank structure of a heat exchanger such as a radiator that is adapted for a motor vehicle.

BACKGROUND OF THE INVENTION

Japanese Patent Applications Laid-Open Publication No. 2005-299989 and No. 2005-326100 disclose a technology of conventional tank structures of heat exchangers in which both end portions of a plurality of tubes are inserted into and fixed to a bottom portion of a tank that is made of aluminum material.

DISCLOSURE OF THE INVENTION Problem(s) to be Solved by the Invention

The conventional inventions, however, have a problem in that they cannot improve coolability of the heat exchangers, because the tubes of the heat exchangers are limited to thin ones for the reason that the tanks thereof could have been deformed to expand outwardly due to thermal shock generated when each tube thereof thermally expands and contracts in a longitudinal direction thereof.

The present invention is made to solve the above-described problem, and its object is to provide a tank structure of a heat exchanger that can prevent a tank from being deformed due to thermal shock generated when each tube of a heat exchanger thermally expands and contracts in a longitudinal direction thereof.

Means for Solving the Problems

According to a first aspect of the present invention there is provided a tank structure of a heat exchanger in which end portions of a plurality of tubes are inserted in and fixed to a bottom portion of a tank that is made of aluminum material, where the tank structure is characterized in that a bead is provided at a position of a tube side heading from a half position of a height of a side wall portion of the tank to extend in a direction perpendicular to a longitudinal direction of the tubes.

According to a second aspect of the present invention there is provided a tank structure of a heat exchanger in which end portions of a plurality of tubes are inserted in and fixed to a bottom portion of a tank that is made of aluminum material, where the tank structure is characterized in that the tank is formed like a vessel to open toward the tubes, a tube plate is fixed to an opening peripheral portion of the tank, in a state where the tube plate and the opening peripheral portion are overlapped with each other, to form a bottom portion of the tank, and W1≧W2×1.5, where W1 is a plate thickness of the tank and W2 is a plate thickness of the tube plate.

EFFECT OF THE INVENTION

In the first invention, the tank structure of the heat exchanger, in which the end portions of the plurality of tubes are inserted in and fixed to the bottom portion of the tank that is made of aluminum material, has the bead that is provided at the position of the tube side heading from the half position of the height of the side wall portion of the tank to extend in the direction perpendicular to the longitudinal direction of the tubes. Therefore, the tank can be prevented from being deformed due to thermal shock generated when the tubes of the heat exchanger thermally expand and contract. In addition, a flow amount of flowing medium in the tank can be uniformed.

In the second invention, the tank structure of the heat exchanger, in which the end portions of the plurality of tubes are inserted in and fixed to the bottom portion of the tank that is made of aluminum material, has the tank that is formed like the vessel to open toward the tubes. The tube plate is fixed to the opening peripheral portion of the tank, in the state where the tube plate and the opening peripheral portion are overlapped with each other, to form the bottom portion of the tank, and W1≧W2×1.5, where W1 is the plate thickness of the tank and W2 is the plate thickness of the tube plate. Therefore, each tube can be allowed to thermally expand and contract in a longitudinal direction thereof, and necessary rigidity of the tank can be ensured.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention will become apparent as the description proceeds when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a rear view showing a tank structure of a heat exchanger of a first embodiment according to the present invention;

FIG. 2 is a cross sectional view taken along a line S2-S2 in FIG. 1;

FIG. 3 is a perspective cross sectional view taken along a line S2-S2 in FIG. 1;

FIG. 4 is a cross sectional view showing a tank structure of a heat exchanger of a second embodiment according to the present invention;

FIG. 5 is a cross sectional view showing a tank structure of a heat exchanger of a third embodiment according to the present invention; and

FIG. 6 is a view showing a tank structure of a heat exchanger of the other embodiment according to the present invention.

DESCRIPTION OF REFERENCE NUMBERS

-   P1 vehicle mounting pin -   R1, R2 reinforcement member -   1 heat exchanger -   2 core part -   3, 4 tank -   5, 6 tube plate -   7 burring hole -   8 tube -   9 fin -   10 outer circumferential wall portion -   11, 12 bead -   13 inlet port -   14 outlet port -   20 tube plate -   21 opening peripheral portion of the tube plate -   22 a part of a seat surface of the tube of the tube plate -   23 opening peripheral portion of the tank -   24 a part of the bead of the tank -   25 skirt-like shaped portion -   30 tank -   31 skirt-like shaped portion

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments according to the present invention will be described with reference to the accompanying drawings.

First Embodiment

Hereinafter, a first embodiment according to the present invention will be described.

Incidentally, the first embodiment in a case where a heat exchanger is applied to a radiator will be described.

FIG. 1 is a rear view showing a tank structure of a heat exchanger of the first embodiment according to the present invention, FIG. 2 is a cross sectional view taken along a line S2-S2 in FIG. 1, and FIG. 3 is a perspective cross sectional view of the same.

First, an entire construction of the first embodiment will be described.

As shown in FIG. 1, a heat exchanger 1 of the first embodiment includes a core part 2, and a pair of tanks 3 and 4 that are arranged above and below the core part 2, respectively.

The core part 2 is composed of a pair of tube plates 5 and 6, a plurality of tubes 8 and a plurality of corrugated fins 9, where the tube plates 5 and 6 are formed like a tray to each open in a direction opposite to a tube 8 side, the tubes 8 have both end portions that are inserted into and fixed to burring holes 7, shown in FIG. 2, of the corresponding tube plates 5 and 6, and the corrugated fins 9 are disposed between the adjacent tubes 8.

In addition, both end portions of the tube plates 5 and 6 are connected with each other to add to the strength thereof through a pair of reinforcement members R1 and R2, respectively.

As shown in FIG. 2 and FIG. 3, both of the tanks 3 and 4 are formed like a vessel to open toward the tube 8 side, and opening peripheral portions thereof are stuck up and joined with inner sides of outer peripheral wall portions 10 of the corresponding tube plates 5 and 6, respectively, to be formed like a box, so that the tanks 3 and 4 are provided with bottom portions, respectively.

In addition, near the bottom portions of side wall portions 11 a and 11 b of the tank 3(4), beads 12 a are provided to extend in a direction perpendicular to the longitudinal direction of the tubes 8 in a state where the beads 12 a sink toward an interior of the tank 3(4). This considerably increases the rigidity of the tank 3(4) in a height direction thereof.

Incidentally, the dimensions of the depth A1 and the height A2 of the beads 12 a may be set appropriately. Further, the beads 12 a are formed in the state where they sink inwardly from the side wall portions 11 a and 11 b of the tank 3(4) in the first embodiment, while they may be formed to project outwardly therefrom.

Further, beads 12 b similar to the beads 12 a are formed above the beads 12 a, which further increases the rigidity of the tank 3(4).

Incidentally, the plate thickness of the tank 3(4) of the first embodiment is set to be 1.8 mm, and the plate thickness of the tube plate 5(6) is set to be 1.0 mm.

In addition, the tank 3 is provided with an inlet port 13 that projects rearward in a state where it is fluidically communicated with the interior of the tank 3. On the other hand, the tank 4 is provided with an outlet port 14 in a state where it is fluidically communicated with the interior of the tank 4.

Further, each tank 3, 4 is provided at its both end portions with vehicle mounting pins P1 that projects in a vertical direction.

Incidentally, in the heat exchanger 1 of the first embodiment, all of construction parts thereof are made of aluminum material, and at least one sides of joining portions of the construction parts are provided with a clad layer (a brazing sheet) of brazing filler material. The construction parts are heat-treated in a not-shown heat furnace to be integrally joined in a state where they are temporally assembled with each other.

Next, the operation of the first embodiment will be described.

The thus-constructed heat exchanger 1 is installed on a motor vehicle in a state where the vehicle mounting pins P1 are fixed on a not-shown radiator core support through mount members that are made of elastic material. The inlet port 13 and the outlet port 14 are connected with connecting pipes of a not-shown engine side.

The high-temperature flowing medium, which flows in the tank 3 through the inlet port 13 from the engine side, is cooled down due to heat transfer by air flow generated when the motor vehicle is running or air flow generated by a not-shown electric motor fan, while the flow medium flows through the core part 2. Then it flows in the tank 4, and it is discharged toward the engine through the outlet port 14. Thus, the heat exchanger 1 functions as a radiator.

Meantime, in the conventional inventions, the tanks could have been deformed to expand due to the thermal shock that is generated when each tubes of the heat exchanger thermally expands and contracts in the longitudinal direction thereof. This does not allow the tubes to be formed thin, and as a result the improvement in coolability of the heat exchanger cannot be realized.

Conversely, in the first embodiment, the beads 12 a are formed near bottom portions of the side wall portions 11 a and 11 b of the tanks 3 and 4 to extend in the direction perpendicular to the longitudinal direction of the tubes 8 as described above, so that they can especially reinforce peripheral portions of the bottom portions of the tanks 3 and 4, thereby preventing the tanks 3 and 4 from being deformed due to the thermal shock that is generated when the tubes 8 expand and contract in the longitudinal direction.

Therefore, the tubes 8 can be formed thin, thereby improving the coolability of the heat exchanger 1.

In addition, the plate thickness of the tank 3(4) is set to be equal to or larger than that of the tube plate 5(6), so that the stress concentration at the tank 3(4) can be decreased by absorbing and dispersing the thermal shock mainly by the tube plate 5(6). Therefore, the durability thereof can be improved.

Further, in the first embodiment, the opening peripheral portions of the tanks 3 and 4 are joined with the inner side of the outer peripheral wall portions 10 of the tube plates 5 and 6, respectively, in the state where they are overlapped with each other, so that the rigidity of these joined portions can be considerably and desirably increased.

Incidentally, as shown in FIG. 2, experiment results show that desired effect can be obtained in a case where the beads 12 a are provided within an area H2 of the tube 8 side heading from a half position of the height H1 of the side wall portions 11 a and 11 b of the tank 3(4).

In the first embodiment, the bottom portions of the tanks 3 and 4 consist of the tube plates 5 and 6, respectively, and accordingly the height H1 of the wall portion of the tank includes the height (the plate thickness) of the tube plate 5, 6.

In other word, the height H1 of the side wall portions of the tank accurately means the height from a tank-side root portion of the tube 8 to upper wall portions of the tank, and it is preferable that the beads 12 a be set nearer the tube 8 side of the tank.

In addition, it is proved that the durability against the thermal expansion and contraction of the tubes 8 in the longitudinal direction can be improved by setting a relationship of W1≧W2×1.5, where W1 is the plate thickness of the tank 3(4) and W2 is the plate thickness of the tube plate 5(6).

In the first embodiment, the beads 12 a are formed and the plate thicknesses are set to satisfy the relationship of W1≧W2×1.5, where W1 is the plate thickness of the tank 3(4) and W2 is the plate thickness of the tube plate 5(6). Nevertheless, according to configurations of the tanks and requested specifications of thermal shock, the plate thicknesses may be set to satisfy W1≧W2×1.5, and no bead may be provided on the tank. On the other hand, only a bead may be provided without satisfying the above relationship, or they may be constructed like the first embodiment.

In addition, the conventional inventions have a problem in that a flow amount of flowing medium flowing through the tubes cannot be uniformed because a flow distribution thereof in the tank 3 tends to incline toward a vicinity of the inlet outlet port 13.

Conversely, in the first embodiment, the flowing medium, which flows in the tank 3 through the inlet port 13, can be easily flow in the longitudinal direction in the tank 3 along the beads 12 a and 12 b. Therefore, the flowing medium can uniformly flow in the tubes 8 from the tank 3, thereby further improving the coolability of the heat exchanger 1.

In addition, the tank 4 is also formed with the beads 12 a and 12 b, and accordingly it can obtain the effects similar to those of the tank 3. There is no possibility of the increase in flow resistance.

Next, the effects of the first embodiment will be described.

As explained above, in the first embodiment, the tank structure of the heat exchanger 1, in which the end portions of the plurality of tubes 8 are inserted into and fixed to the tube plates 5 and 6 of the tanks 3 and 4 that are made of the aluminum material, has the beads 12 a that extend in the direction perpendicular to the longitudinal direction of the tubes 8, being arranged at the position of the tube 8 side heading from the half position of the height H1 of the side wall portions 11 a and 11 b of the tank 3(4). Therefore, the tank 3(4) can be prevented from being deformed due to the thermal shock that is generated when the tubes 8 of the heat exchanger 1 thermally expand and contract in the longitudinal direction thereof, and the flow amount of the flowing medium in the tank 3 can be uniformed.

In addition, the tank 3(4) is formed like the vessel, and its opening peripheral portion are joined with the tube pate 5(6), in the state where they are overlapped with each other to be formed like the box, so that the bottom portion of the tank 3(4) can be formed. In addition, the plate thicknesses are set to satisfy the relationship of W1≧W2×1.5, where W1 is the plate thickness of the tank 3(4) and W2 is the plate thickness of the tube plate 5(6). Therefore, it can allow the tubes 8 to thermally expand and contract in the longitudinal direction, ensuring necessary rigidity of the tank 3(4).

Second Embodiment

Hereinafter, a second embodiment according to the prevent invention will be described.

In the second embodiment, parts and portions similar to those of the first embodiment are indicated by the same reference numbers, and their explanation will be omitted, while only their different parts will be described.

FIG. 4 is a cross sectional view illustrating a tank structure of a heat exchanger of the second embodiment.

As shown in FIG. 4, in the second embodiment, a tube plate 20 that is formed like a tray to open toward a tube 8 side is employed instead of the tube plate 5(6) that is formed like the first embodiment. In addition, the tube plate 20 is press-fitted in an opening peripheral portion 23 of a tank 3(4), and they are joined with each other by brazing in a state where they are overlapped with each other. These constructions are different from the first embodiment.

Specifically, an opening peripheral portion 21 and a part 22 of seat surfaces, for the tubes 8, of the tube plate 20 are fixed by brazing with a skirt-like shaped portion 25 that has a cross section like an L-letter shape formed by the opening peripheral portion 23 of the tank 3(4) and a part 24 of beads 12 a, in a state where they are surface-contacted with the skirt-like shaped portion 25, when the tube plate 20 are press-fitted in the tank 3(4).

Therefore, the second embodiment can obtain the following effects in addition to those of the first embodiment. Contact areas of the tubes 8 and the tank 3(4) can be increased, thereby being well brazed with each other and increasing the rigidity of their peripheral portions.

In addition, the tube plate 20 and the tank 3(4) can be positioned relative to each other by contacting the part 22 of the seat surfaces of the tubes 8 with the part 24 of the bead 12 when the tube plate 20 is press-fitted in the tank 3(4). Therefore, they can be brazed with each other, being assembled with high accuracy.

Third Embodiment

Herein after, a third embodiment according to the present invention will be described.

In the third embodiment, parts and portions similar to those of the second embodiment are indicated by the same reference numbers, and their explanation will be omitted, while only their different parts will be described.

FIG. 5 is a cross sectional view illustrating a tank structure of a heat exchanger of the third embodiment.

As shown in FIG. 5, in the third embodiment, the beads 12 a and 12 b, which are explained in the first embodiment, are removed, and it employs a tank 50, which is shaped like a vessel to open toward tubes 8. In addition, a tube plate 20 and a skirt-like shaped portion 31 are fixed with each other by brazing in a state where the tube plate 20 is press-fitted in an inner side of the skirt-like shaped portion 31, where the tube plate 20 is constructed as explained in the second embodiment, and the skirt-like shaped portion 31 has a cross section formed like an L-letter shape and is formed around an opening peripheral portion thereof. These constructions are different from the second embodiment.

Specifically, the opening peripheral portion 21 of the tube plate 20 and a part of seat surfaces of the tubes 8 are fixed with the skirt-like shaped portion 31 of the tank 3(4) by brazing in a state where they are surface-contacted with the inner side of the skirt-like portion 31, when the tube plate 20 is press-fitted in the tank 3(4).

Similarly to the second embodiment, in the third embodiment, the tube plate 20 and the tank 3(4) can be well brazed due to the increase in the contact area thereof, thereby obtaining necessary rigidity of the peripheral portions.

As the embodiments have been explained, but the present invention is not limited to the embodiments, and its design changes and modifications are contained in the present invention as long as they do not depart from the subject of matter of the present invention.

For example, the heat exchanger employs the radiator in the embodiments, while it may employ a general heat exchanger such as an intercooler.

In addition, as shown in FIG. 6, it may employ a tank 41 that has a cross section shaped like a U-letter to open in a front and back direction of a motor vehicle, its opening portion being closed up by a lid plate 40. In this case, a bead 42, which is formed similarly to the first embodiment, may be provided on a portion near a bottom portion of a tank 41 on one side wall portion 41 of side the wall portions 41 a and 41 b of the tank 41, and a portion near a bottom portion of the other side wall portion 41 b thereof may be overlapped with the lid plate 40, in order to increase the rigidity of a peripheral portion near the bottom portion of the tank 41. 

1. A tank structure of a heat exchanger in which end portions of a plurality of tubes are inserted in and fixed to a bottom portion of a tank that is made of aluminum material, the tank structure characterized in that a bead is provided at a position of a tube side heading from a half position of a height of a side wall portion of the tank to extend in a direction perpendicular to a longitudinal direction of the tubes.
 2. The tank structure of the heat exchanger according to the claim 1, wherein the tank is formed like a vessel to open toward the tubes, and wherein a tube plate, which is formed like a tray to open toward the tubes, forms the bottom portion of the tank by being fixed to a skirt-like shaped portion which has a cross section shaped like an L-letter and is formed around an opening peripheral portion of the tank in a state where the tube plate is press-fitted in to be overlapped with an inner side of the skirt-like shaped portion.
 3. A tank structure of a heat exchanger in which end portions of a plurality of tubes are inserted in and fixed to a bottom portion of a tank that is made of aluminum material, the tank structure characterized in that the tank is formed like a vessel to open toward the tubes, wherein a tube plate is fixed to an opening peripheral portion of the tank, in a state where the tube plate and the opening peripheral portion are overlapped with each other, to form a bottom portion of the tank, and wherein W1≧W2×1.5, where W1 is a plate thickness of the tank and W2 is a plate thickness of the tube plate.
 4. The tank structure of the heat exchanger according to claim 3, wherein the tank is formed like a vessel to open toward the tubes, and wherein a tube plate, which is formed like a tray to open toward the tubes, forms the bottom portion of the tank by being fixed to a skirt-like shaped portion which has a cross section shaped like an L-letter and is formed around an opening peripheral portion of the tank in a state where the tube plate is press-fitted in to be overlapped with an inner side of the skirt-like shaped portion. 